Numerous color management solutions have been introduced in an effort to obtain color consistency across different software applications and imaging devices. However, none of these solutions and standards has yet been successful in satisfying all the needs of the vast majority of new and existing digital imaging users.
Color is a result of interactions between light sources, physical objects, and the human visual system. The color management challenge begins with modeling the complex and variable nature of these physical and psychological effects. Further, each device, whether a scanner, monitor, or printer, has a particular range of colors that it is capable of producing, known as the device gamut. The gamut of a device is determined by the physical characteristics of the device itself, as well as the ambient lighting. In today's open computing environment, constraints are imposed by the differing capabilities and proprietary technologies in devices, applications, operating systems, and networks. For example, the gamuts of devices of the same types may vary. For instance, the gamuts of scanners depend on the technology used (flatbed, drum, charge-coupled device) as well as the media scanned (reflective vs. transparent). With monitors, the gamut depends on the composition of the phosphors. With printers, the gamut varies depending on the inks and media used.
Given the current available tools, matching colors across devices and workflows is not an easy task. Current color management solutions tend to be difficult to use as operating systems, applications, and device drivers often implement color management in proprietary, inconsistent, and conflicting ways.
Troubleshooting color problems likewise is complicated and obscure for all but the most knowledgeable user. Device calibration is often slow and difficult. Practically, this means that a significant amount of color expertise is required to produce the most basic results. Because most end users cannot precisely articulate their needs, there is a lack of understanding of what is required at the architectural or technical level to reproduce consistent color results on day-to-day basis.
The quest for consistent color is not a new phenomenon. In 1994, the International Color Consortium (ICC) was established for the purpose of creating, promoting and encouraging the standardization and evolution of an open, vendor-neutral, cross-platform color management system architecture and components. The outcome of this cooperation was the development of the ICC profile specification.
The intent of the ICC profile format was to provide a cross-platform device profile format that could be used to translate color data created on one device into another device's native color space. The general idea was that acceptance of this format by operating system vendors would allow end users to transparently move profiles and images with embedded profiles among different operating systems and applications and allow device manufacturers to create a single profile for multiple operating systems.
Color management systems today provide very little flexibility in controlling preferred rendering intent. Rendering intent typically controls the gamut map model and parameters involved in subjectively transforming the media content from the color gamut capabilities of done today to different capabilities of a second device. Historically two approaches have been taken. The intrinsic device or application approach processes all of the rendering intent or gamut mapping within the vendor's device of application. This is what happens with standard color space workflows (sRGB). The application might optionally provide some proprietary rudimentary control such as a digital still camera providing sRGB-I and sRBG-II. The second approach is to provide a rudimentary flag to give a “hint” for which gamut mapping algorithm should be used. This approach is taken by PostScript, PDF and ICC workflows. The flag might be a simple enumeration of four values that have little documented meaning, such as saturation, perceptual, absolute calorimetric and relative colormetric.
Neither of these prevalent approaches provides for the opportunity for hardware vendors to optimize the look and feel of their devices by default in such a manner that end users and applications reasonably can determine whether to override the defaults or provide different defaults. The ICC-type solution results in a series of rendering intent conflicts between devices, applications and users. The conflicts tend to be resolved in an ad-hoc manner. This results in significant frustration and confusion by end users and vendors on what color management processing will actually be accomplished under each set of conditions.